"Fukushima is the biggest industrial catastrophe in the history ofmankind," Arnold Gundersen, a former nuclear industry senior vicepresident, told Al Jazeera.

Japan's 9.0 earthquake on March 11 caused a massive tsunami thatcrippled the cooling systems at the Tokyo Electric Power Company's(TEPCO) nuclear plant in Fukushima, Japan. It also led to hydrogenexplosions and reactor meltdowns that forced evacuations of thoseliving within a 20km radius of the plant.

Gundersen, a licensed reactor operator with 39 years of nuclear powerengineering experience, managing and coordinating projects at 70nuclear power plants around the US, says the Fukushima nuclear plantlikely has more exposed reactor cores than commonly believed.

"Fukushima has three nuclear reactors exposed and four fuel coresexposed," he said, "You probably have the equivalent of 20 nuclearreactor cores because of the fuel cores, and they are all in desperateneed of being cooled, and there is no means to cool them effectively."

TEPCO has been spraying water on several of the reactors and fuelcores, but this has led to even greater problems, such as radiationbeing emitted into the air in steam and evaporated sea water - as wellas generating hundreds of thousands of tons of highly radioactive seawater that has to be disposed of.

"The problem is how to keep it cool," says Gundersen. "They arepouring in water and the question is what are they going to do withthe waste that comes out of that system, because it is going tocontain plutonium and uranium. Where do you put the water?"

Even though the plant is now shut down, fission products such asuranium continue to generate heat, and therefore require cooling.

"The fuels are now a molten blob at the bottom of the reactor,"Gundersen added. "TEPCO announced they had a melt through. A melt downis when the fuel collapses to the bottom of the reactor, and a meltthrough means it has melted through some layers. That blob isincredibly radioactive, and now you have water on top of it. The waterpicks up enormous amounts of radiation, so you add more water and youare generating hundreds of thousands of tons of highly radioactivewater."

Independent scientists have been monitoring the locations ofradioactive "hot spots" around Japan, and their findings aredisconcerting.

"We have 20 nuclear cores exposed, the fuel pools have several coreseach, that is 20 times the potential to be released than Chernobyl,"said Gundersen. "The data I'm seeing shows that we are finding hotspots further away than we had from Chernobyl, and the amount ofradiation in many of them was the amount that caused areas to bedeclared no-man's-land for Chernobyl. We are seeing square kilometresbeing found 60 to 70 kilometres away from the reactor. You can't cleanall this up. We still have radioactive wild boar in Germany, 30 yearsafter Chernobyl."

TEPCO announced that the accident probably released more radioactivematerial into the environment than Chernobyl, making it the worstnuclear accident on record.

Meanwhile, a nuclear waste advisor to the Japanese government reportedthat about 966 square kilometres near the power station - an arearoughly 17 times the size of Manhattan - is now likely uninhabitable.

In the US, physician Janette Sherman MD and epidemiologist JosephMangano published an essay shedding light on a 35 per cent spike ininfant mortality in northwest cities that occurred after the Fukushimameltdown, and may well be the result of fallout from the strickennuclear plant.

The eight cities included in the report are San Jose, Berkeley, SanFrancisco, Sacramento, Santa Cruz, Portland, Seattle, and Boise, andthe time frame of the report included the ten weeks immediatelyfollowing the disaster.

"There is and should be concern about younger people being exposed,and the Japanese government will be giving out radiation monitors tochildren," Dr MV Ramana, a physicist with the Programme on Science andGlobal Security at Princeton University who specialises in issues ofnuclear safety, told Al Jazeera.

Dr Ramana explained that he believes the primary radiation threatcontinues to be mostly for residents living within 50km of the plant,but added: "There are going to be areas outside of the Japanesegovernment's 20km mandatory evacuation zone where radiation is higher.So that could mean evacuation zones in those areas as well."

Gundersen points out that far more radiation has been released thanhas been reported.

"They recalculated the amount of radiation released, but the news isreally not talking about this," he said. "The new calculations showthat within the first week of the accident, they released 2.3 times asmuch radiation as they thought they released in the first 80 days."

According to Gundersen, the exposed reactors and fuel cores arecontinuing to release microns of caesium, strontium, and plutoniumisotopes. These are referred to as "hot particles".

"We are discovering hot particles everywhere in Japan, even in Tokyo,"he said. "Scientists are finding these everywhere. Over the last 90days these hot particles have continued to fall and are beingdeposited in high concentrations. A lot of people are picking these upin car engine air filters."

Radioactive air filters from cars in Fukushima prefecture and Tokyoare now common, and Gundersen says his sources are finding radioactiveair filters in the greater Seattle area of the US as well.

The hot particles on them can eventually lead to cancer.

"These get stuck in your lungs or GI tract, and they are a constantirritant," he explained, "One cigarette doesn't get you, but over timethey do. These [hot particles] can cause cancer, but you can't measurethem with a Geiger counter. Clearly people in Fukushima prefecturehave breathed in a large amount of these particles. Clearly the upperWest Coast of the US has people being affected. That area got hitpretty heavy in April."

Blame the US?

In reaction to the Fukushima catastrophe, Germany is phasing out allof its nuclear reactors over the next decade. In a referendum votethis Monday, 95 per cent of Italians voted in favour of blocking anuclear power revival in their country. A recent newspaper poll inJapan shows nearly three-quarters of respondents favour a phase-out ofnuclear power in Japan.

Why have alarms not been sounded about radiation exposure in the US?

Nuclear operator Exelon Corporation has been among Barack Obama'sbiggest campaign donors, and is one of the largest employers inIllinois where Obama was senator. Exelon has donated more than$269,000 to his political campaigns, thus far. Obama also appointedExelon CEO John Rowe to his Blue Ribbon Commission on America'sNuclear Future.

Dr Shoji Sawada is a theoretical particle physicist and ProfessorEmeritus at Nagoya University in Japan.He is concerned about the types of nuclear plants in his country, andthe fact that most of them are of US design.

"Most of the reactors in Japan were designed by US companies who didnot care for the effects of earthquakes," Dr Sawada told Al Jazeera."I think this problem applies to all nuclear power stations acrossJapan."

Using nuclear power to produce electricity in Japan is a product ofthe nuclear policy of the US, something Dr Sawada feels is also alarge component of the problem.

"Most of the Japanese scientists at that time, the mid-1950s,considered that the technology of nuclear energy was under developmentor not established enough, and that it was too early to be put topractical use," he explained. "The Japan Scientists Councilrecommended the Japanese government not use this technology yet, butthe government accepted to use enriched uranium to fuel nuclear powerstations, and was thus subjected to US government policy."

As a 13-year-old, Dr Sawada experienced the US nuclear attack againstJapan from his home, situated just 1400 metres from the hypocentre ofthe Hiroshima bomb.

"I think the Fukushima accident has caused the Japanese people toabandon the myth that nuclear power stations are safe," he said. "Nowthe opinions of the Japanese people have rapidly changed. Well beyondhalf the population believes Japan should move towards naturalelectricity."

A problem of infinite proportions

Dr Ramana expects the plant reactors and fuel cores to be cooledenough for a shutdown within two years."But it is going to take a very long time before the fuel can beremoved from the reactor," he added. "Dealing with the cracking andcompromised structure and dealing with radiation in the area will takeseveral years, there's no question about that."

Dr Sawada is not as clear about how long a cold shutdown could take,and said the problem will be "the effects from caesium-137 thatremains in the soil and the polluted water around the power stationand underground. It will take a year, or more time, to deal withthis".

Gundersen pointed out that the units are still leaking radiation.

"They are still emitting radioactive gases and an enormous amount ofradioactive liquid," he said. "It will be at least a year before itstops boiling, and until it stops boiling, it's going to be crankingout radioactive steam and liquids."

Gundersen worries about more earthquake aftershocks, as well as how tocool two of the units.

"Unit four is the most dangerous, it could topple," he said. "Afterthe earthquake in Sumatra there was an 8.6 [aftershock] about 90 dayslater, so we are not out of the woods yet. And you're at a pointwhere, if that happens, there is no science for this, no one has everimagined having hot nuclear fuel lying outside the fuel pool. They'venot figured out how to cool units three and four."

Gundersen's assessment of solving this crisis is grim.

"Units one through three have nuclear waste on the floor, the meltedcore, that has plutonium in it, and that has to be removed from theenvironment for hundreds of thousands of years," he said. "Somehow,robotically, they will have to go in there and manage to put it in acontainer and store it for infinity, and that technology doesn'texist. Nobody knows how to pick up the molten core from the floor,there is no solution available now for picking that up from thefloor."

Dr Sawada says that the creation of nuclear fission generatesradioactive materials for which there is simply no knowledge informingus how to dispose of the radioactive waste safely.

"Until we know how to safely dispose of the radioactive materialsgenerated by nuclear plants, we should postpone these activities so asnot to cause further harm to future generations," he explained. "To dootherwise is simply an immoral act, and that is my belief, both as ascientist and as a survivor of the Hiroshima atomic bombing."

Gundersen believes it will take experts at least ten years to designand implement the plan.

"So ten to 15 years from now maybe we can say the reactors have beendismantled, and in the meantime you wind up contaminating the water,"Gundersen said. "We are already seeing Strontium [at] 250 times theallowable limits in the water table at Fukushima. Contaminated watertables are incredibly difficult to clean. So I think we will have acontaminated aquifer in the area of the Fukushima site for a long,long time to come."

Unfortunately, the history of nuclear disasters appears to backGundersen's assessment.

"With Three Mile Island and Chernobyl, and now with Fukushima, you canpinpoint the exact day and time they started," he said, "But theynever end."